In Germany, the country in question here, the current stance of the federal supreme court (links to Wikipedia case below, ruling is dated 12/2018) seems to be that even photography of public domain works can retain copyright with the museum. To be clear, I find both that stance and the behaviour of the organisation behind the museum appaling but I'm really not sure how US copyright law or unrealized EU directives are all that relevant. Intellectual property rights in Germany are complicated and when in doubt usually err on the side of copyright holders.

http://ipkitten.blogspot.com/2019/02/digitized-images-of-wor...

https://dejure.org/dienste/vernetzung/rechtsprechung?Text=I%...